This is a renewal of the Pediatric ACTG unit for the Los Angeles area. The LAPAC consists of 7 clinical study sites (UCLA Med. Ctr., Childrens Hosp., of LA, Harbor-UCLA, Mem. Med. Ctr. Long Beach, Cedars-Sinai Med. Ctr., Martin Luther King Jr. Hosp., and Kaiser Perm. Med. Group). This consortium has successfully worked together for the past eight years and has enrolled a significant number of HIV infected women, children and adolescents representing 79% ethnic minorities and other disenfranchised populations into AGTG trials (n=336). UCLA is the main administrative data entry, coordinating and laboratory site with a well integrated network and infrastructure at our subsites. We have established effective liaisons with an LA County surveillance study, community health centers for HIV screening of pregnant women, a county- wide social service network for HIV+ children, community representatives and a pediatric Community Advisory Board. All centers provide primary care for HIV infected children and adolescents and three are also designated perinatal centers, which can enroll HIV+ pregnant women into clinical trials with liaisons for continued care and access to clinical trials. This consortium provides clinical care for 80% of the HIV exposed or infected children in LA (n=424) and is a catchment area for 75,000 of the deliveries. Our unit has made major scientific contributions both in the design and implementation of the overall pediatric/perinatal scientific agenda including studies to enhance the knowledge of pathogenesis and to significantly reduce perinatal transmission, to develop new methods of early diagnosis in infected infants, to provide insight into the actors associated with disease progression in infants and children and to improve the treatment and quality of lives of infected children and adolescents. We have a very strong record in advancing the science, providing leadership and also contributing to the productivity of the national pediatric effort. We plan to enroll a minimum of 50 patients/yr into clinical trials with an emphasis on perinatal and phase I/II studies, and to follow 87 continuing patents. We plan to enroll 28 new HIV infected pregnant women and/or newborns, 14 HIV infected children or adolescents into primary therapy and 8 into studies of opportunistic infections. Our goals are integrated into the scientific agenda and include the reduction of perinatal transmission to <2%, early aggressive treatment of infants during primary infection and the evaluation of new potent combination therapies to evince and prolong the lives of children(adolescents already infected with HIV. We will also enhance our outreach to identify HIV+ pregnant women and adolescents for entrance into clinical trials. Our core and developmental laboratories in both virology and immunology have the capability to provide new innovative assays to enhance the overall scientific agenda and support the clinical trials.